Usually, metallic guidewires are used as information transmission medium. With the rapid development of optical cable technologies, the optical cable information sensing technologies have a tendency to substitute the metallic guidewires for advantages in many aspects, thus becoming a research focus. By using an optical cable as an information transmission medium, a high-temperature resistant sensing optical cable is used for implementing information transmission, and is good in high temperature resistance, simple in structure, strong in antijamming capability, and flexible in use, etc.
At present, factors restricting further development of the high-temperature resistant optical cables are as follows: optical cable manufacturing technologies, and preparation of optical cables good in microbending property, high in tensile strength, long in single-cable length, low in wear, good in fatigue resistance and long in storage period is the most important. Transmission properties, mechanical properties and environmental properties of the optical fibers mainly depend on properties of the coatings and outer protective layer materials. Therefore, it is of vital importance to select proper coating and outer protective layer materials. The traditional high-temperature resistant and sensing optical cables are formed by weaving or coating the surface of the optical fibers with organdy or aramid yarn and then performing thermocuring or ultraviolet (UV) curing. The optical cables prepared by this method are large in outer diameter and complicated in process, and thus have no practical applicability.
When common optical cable outer protective layer materials such as polyethylene and polrvinyl chloride are very thin in thickness (for example, 0.1 mm), they are poor in antiaging capability and fragile at low temperature. Although low-temperature properties of materials good in antiaging capability, such as nylon, are improved, a thermal expansion coefficient thereof is up to 10−4/T, two orders of magnitude higher than that (10−6/T) of the optical fiber, which causes the optical cables to generate great microbending loss at low temperature.
Therefore, it is urgent for the inventor of the present disclosure to design a new technology to solve these problems.